Process of making thymol from nitrocymene



R. M. cow,

PROCESS OF MAKING THYMOL FROM NITROCYMENE. APPLICATION FILED DEC. 31 I919- 1,37s,939,' Patented May 24,1921.

g Le -a in mm I I IHH IHHI Q/bode 'the following sulfuric acid in the anode space ROBERT M. COLE, 01Ev SANDUSKY, OH IO.

. PROCESS OF MAKING Specification of Letters latent.

TEYMOL FROM NIIROCYMENE.

Application filed December 3,1919. Serial No. 342,290.

T 0 all whom it may concern: Be it known that 1, ROBERT M. COLE, a citizen of the United States of America, and a resident of Sandusky, county of Erie, and State of Ohio, have invented certainnew and useful Improvements inProcesses of Making Thymol from Nitrocymene, of which is a specification. .The main objects of this invention are to provide an improved process of obtaining thymol (l-methyl: t-isopropyl: 5-hydroxybenzol); to provide a new and improved process of treating nitro-cymene for the purpose of obtaining thymol; and to provide a process for this purpose which is simple and safe to follow and which will pro ducea substantial quantity of-thymol at a comparatively low expense.

This new and improved essentially in the electrolytic reduction of nitro-cymene and the subsequent diazotization and reduction of the para-amidocymenol produced by electrolytic action. The electrolytic reduction is efiected in the presence ofsulfuric acid and the diazotization involves the use of usual stannous chloridfi The accompanying drawing illustrates diagrammatically an apparatus suitable for carrying out the electrolyticreduction.

The.vessel preferably comprises a cylindrical tank 1 with a lining of lead 2, which also serves as-the .anode. In this-vessel is placed a container 3, sufficiently porous to permit the passage of ionsfrom one "chamber to another but nearly impervious to the passage of molecules, and within theicontainer is arranged a carbon or copper cathode" in the form of cylinder 4. Within this latter cylinder is also arranged a stirrer or agitator 5,.pref- .erably made of stoneware or lead-covered iron. The anode chamber is charged'with 30 B. (sp. gr. 1.26) sulfuric acid, and the cathode space is charged with25 Be. (sp. gr. 1.21) sulfuric acid. The strength of the I 1s ma ntained throughout the process by the addi-' tion of water which is added in suitable quant'ties as the reaction proceeds. The

nitrocymene is placed inthe cathode space in a quantity approximately'fifty per" cent.

of the weight of one hundred per cent. acid. The electrolytic action is obtained by the use of a current density'of 5% amperes per square decimeter of cathode surface, and a potential of three volts. During the process,

process consists 4 on, NOr NH:

-Electrolysis- Diazotization a hollow perforatedthe temperature is maintained atbetween 75 and 85 C, During the electrolytic ac- Patented'May 24, 1921. 7

tion, the nitro-cymene is kept in thorough emulslon in the aqueous acid solution by. means of the agitator or stirrer.

After "the electrolytic action has been maintained for a suitable length of time, the contents of the-vessel are allowed to cool following which the unchanged nitro-cy mene is separated for reuse, and the 1.

methyl 2 amino 4 isopropyl 5 hydroxy benzol is filteredofi' from the remaining acid S0l11t1-0l'1,WhI0l1' latter is strengthened for di 111112 i eme y amino 4 iso ro l5'h droxy benzol is then diazotized an d furthzr reduced n an alkaline solution of stannous chlorld, 1n the usual and well-known man-- ner, with theresulting production of thymol.- The reaction tak ng place in following out thisprocess may be illustrated as-follows:

HO HO Although but one specific method of following out this process is herein described,

it will be understood that some of the steps thereof'ma be altered or modified without departing rom the spirit of the invention as defined by the following claims.

I claim: 1. The process of consists in the electrolytic reduction of mtro-cymene and'the diazotizationand re duction of the resulting-1 methyl, 2 amino a isopropyl 5 hydroxy benzol.

2;"Th'e process of making thymol which (consists in the electrolyticreduction ofnitrocymene in sulfuric acid, and thediazotiza tion and reduction of the resulting 1 methyl: 2 amino i isopropyl 5 hydroxy benzol.

3. The process of making thymol which consists in the electrolytic reduction of nitro-cymene in sulfuric acid the strength of which in the anode and cathode chambers is substantially in the proportions of six'fto five respectively, and the diazotization and reduction of the resulting 1 methyl 2' amino 1 isopropyl 5 hydroxy benzol. 4. The process of making thyinol which consists in the electrolytic reduction. of nitromaking thymol which cymene in sulfuric acid, wherein the strength of the acid in the anode chamber is substantially 30% B. and the strength of the acid in the cathode chamber is substantially 25% B., and the diazotization and reduction of the resulting 1 methyl 2 amino 4 isopropyl 5 hydroxy benzol.

5. The process of making thymol which consists in the electrolytic reduction of nitro-cymene and the diazotization and re duction of the resulting 1 methyl 2 amino 4 isopropyl 5 hydroxy benzol in an alkaline solution.

6. The process of making thymol which consists in the electrolytic reduction of nitrocymene and the dia-zotization and reduction tro-cymene in sulfuric acid, wherein the strength of the acid in the anode chamber is substantially 30% B. and the strength of the acid in the cathode chamber is substantially 25% B., and thediazotization and reduction of the resulting 1 methyl 2 amino 4 isopropyl 5 hydroxy benzol in an alkaline solution of stannous chlorid.

Signed at Sandusky this 29th day of November 1919.

ROBT. M. COLE. 

